Systems, apparatus and methods for optimizing the pyrolysis of biomass using thermal expansion

ABSTRACT

A process for pyrolyzing biomass comprises pyrolyzing cellulosic biomass in a fast pyrolysis chamber by heating the cellulosic biomass to a pyrolyzation temperature to generate a pyrolysis vapor flow therefrom. The pyrolysis vapor flow is directed from the fast pyrolysis chamber along a vapor flow conduit to a condensation trap at a temperature sufficient to condense the vapor to liquid and generate a thermal gradient along the vapor flow conduit between the pyrolysis chamber and condensation trap. A majority of the pyrolysis vapor flow along the vapor flow conduit to the condensation trap is achieved by natural convection. Systems that can practice this process are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 13/799,852filed on Mar. 13, 2013, the contents of which application is hereinincorporated by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to the field of pyrolysis and, more particularly,to more efficient systems and processes for pyrolysis of biomass.

BACKGROUND

The United States faces substantial environmental issues from continuingreliance on existing energy sources. The burning of fossil fuels, suchas coal and natural gas, results in the emission of excessive amounts ofcarbon dioxide into the atmosphere. The use of nuclear power raises thespecter of ecological damage through the accidental release of radiationinto the environment, as well as difficulties in safely disposing ofspent nuclear fuel. Hydroelectric projects can disrupt local ecosystems,resulting in major reductions in fish populations, negative impacts onnative and migratory birds and damage to river systems.

In recent years, biomass has gained popularity as anenvironmentally-sound alternative renewable energy source. Biomass, orthe fuel products derived from it, can be burned to produce power.Unlike fossil fuels, however, carbon dioxide released from the burningof biomass does not contribute to the overall carbon dioxide content ofthe atmosphere. This is true because biomass is part of the world'satmospheric carbon cycle. For this reason, biomass is viewed as arenewable, carbon-neutral fuel.

Processing facilities for forest products, used automotive tires, andused railroad cross ties are substantial sources of biomass. The typicalforest products facility uses some of its biomass in processing, whilethe remainder of the biomass is seen as a byproduct. One type of forestproducts processor that produces a large volume of biomass byproduct isa chip mill that processes small-sized timber. In the chip mill, logsare debarked and then ground into chips for transporting to other millsfor further processing. Another type of sawmill is a chip and sawfacility (“CNS facility”). A CNS facility produces dimensional lumberfrom timber that has a diameter ranging from mid-sized to small.Substantial sources of biomass are also available from other forestproducts facilities, such as large log processing plants, plywoodplants, and oriented strand board (OSB) plants, among others.

A typical CNS facility generates an average of more than five-hundredtons of dry biomass byproducts per day. (According to Marks MechanicalEngineering Handbook, the standard for “dry” is defined as twelvepercent moisture content or less.) These biomass byproducts typicallyinclude white chips, bark, sawdust, and/or wood shavings. The whitechips produced by a CNS facility are generally sold to paper-producingmills for processing into paper and cellulose products. The bark,sawdust and shavings are either used at the CNS facility itself as athermal energy source or sold as a byproduct. Pellet mills have begun touse the white chips and small logs for manufacturing pellets of highdensity biomass for use a fuel in combustion burner systems. Thebyproducts of lumber production facilities such as sawdust, planer millshavings, and bark are not usable for paper production or for pelletproduction.

Pyrolysis is one process used to produce energy products from biomass.Pyrolysis utilizes temperatures of between about 450-600 degrees Celsiusto rapidly heat biomass in the absence of oxygen. The process results inthe creation of three products: bio-oil (pyrolysis oil), char, andnon-condensing gases. All three products are combustible. Pyrolysis ofbiomass produces pressure that limits the size and processing capacityof the unit.

Fuel needed to create and maintain such high temperatures in systemsutilizing pyrolysis can represent a major operational expense. For thisreason, it is desirable to employ systems that make the most of the heatproduced. There are a number of strategies for accomplishing this.

One strategy employs techniques meant to optimize the transfer ofthermal energy to individual particles of biomass within a pyrolysischamber. This can be accomplished through the use of organic heatcarriers such as hot char and inorganic heat carriers, such as sand.These particularized heat carriers circulate within the pyrolysischamber and radiate heat to the biomass. Other techniques involverapidly moving particles of feedstock within a pyrolysis chamber so asto force the particles into nearly continual contact with the hot wallsof the chamber. Still other techniques circulate a heated gas streamthrough a pyrolysis chamber to transfer heat to the particles ofbiomass. Another strategy involves capturing the hot exhaust resultingfrom pyrolytic reactions in the pyrolysis chamber and re-circulatingthat hot exhaust to other parts of the system. Yet another strategyinvolves insulating the pyrolysis chamber to deter heat loss through thewalls of the chamber.

What is needed are pyrolysis systems and methods that improve upon theconservation and re-use of existing heat while being able to producepyrolysis oil at lower pressures than conventional systems. Also neededare pyrolysis systems and methods that are easily collocated withbiomass generating facilities.

SUMMARY OF THE INVENTION

In view of the foregoing background, an advantageous aspect of theinvention is a process for pyrolyzing biomass that involves pyrolyzingbiomass in a pyrolysis chamber by heating the biomass to a pyrolyzationtemperature to generate a pyrolysis vapor flow therefrom. The pyrolysisvapor flow is directed from the pyrolysis chamber along a vapor flowconduit to a condensation trap at a temperature sufficient to condensethe vapor to liquid and generate a thermal gradient along the vapor flowconduit between the pyrolysis chamber and condensation trap. In thismethod aspect, a majority of the pyrolysis vapor flow along the vaporflow conduit to the condensation trap is achieved by natural convection.Several pyrolysis systems capable of performing this method are alsodescribed.

In a first system aspect of the invention, a pyrolysis system includes avertically oriented pyrolysis unit having a pyrolysis chamber elongatedalong a vertical axis thereof and a combustion chamber arrangedgenerally concentrically and sharing a common heat-conducting wall withthe pyrolysis chamber. A combustion source is in thermal communicationwith a lower end of the combustion chamber for heating the pyrolysischamber. A biomass input port is proximate an upper end of the pyrolysischamber for allowing biomass introduced therein to fall towards a lowerend of the pyrolysis chamber. A pyrolysis liquid collection unit is invapor communication with the pyrolysis chamber for condensing thepyrolysis vapor to liquid.

In a second system aspect of the invention, a pyrolysis system includesa biomass input port at a proximal end of an auger housing for feedingbiomass into an auger housing chamber. An auger is coupled to thebiomass input port for receiving biomass therefrom and moving thebiomass along a length of the auger into a pyrolysis zone of the augerhousing positioned between the proximal end and a distal end. The augerhas a spiral blade positioned along its length. A heat source is coupledto the auger housing and is positioned proximate the pyrolysis zone forproviding sufficient heat to pyrolyze biomass in the pyrolysis zone. Achar output port is positioned at the distal end for removing charproduced during pyrolysis from the auger. A pyrolysis liquid collectionunit is in vapor communication with the auger for condensing thepyrolysis vapor to liquid.

In a third system aspect of the invention, a pyrolysis system includes abiomass input port positioned about a proximal end of an inertiaconveyor housing for feeding biomass into an inertia conveyor housingchamber. An inclined inertia conveyor is coupled to the biomass inputport and extends within the inertia conveyor housing for moving thebiomass along a length of the inclined inertia conveyor to a pyrolysiszone positioned between the proximal end and a distal end of the inertiaconveyor housing. A heat source is coupled to the inertia conveyorhousing and is positioned proximate the pyrolysis zone for providingsufficient heat to pyrolyze biomass in the pyrolysis zone. A char outputport is positioned proximate the distal end for removing char producedduring pyrolysis from the inertia conveyor. A pyrolysis liquidcollection unit is in vapor communication with the inertia conveyor forcondensing the pyrolysis vapor to liquid.

These aspects of the invention, along with other additional aspects,embodiments, and features will be better understood by referring to theaccompanying drawings and the Detailed Description of PreferredEmbodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, partially in cross-section, of a first embodimentof a batch pyrolysis system in accordance with an embodiment of theinvention;

FIG. 2 is a perspective view a pyrolysis unit and heat source usefulwith pyrolysis system embodiments of the invention;

FIG. 3 is a perspective view a pyrolysis unit and heat source with anelectric heater useful with pyrolysis system embodiments of theinvention;

FIG. 4 is a schematic, partially in cross-section, of a second pyrolysissystem in accordance with an embodiment of the invention;

FIG. 5 is a perspective view of an electric pre-heater useful with thesystem of FIG. 4;

FIG. 6 is a schematic, partially in cross-section, of an auger basedpyrolysis system in accordance with an embodiment of the invention; and

FIG. 7 is a schematic, partially in cross-section, of an inertiaconveyor based pyrolysis system in accordance with an embodiment of theinvention.

DETAILED DESCRIPTION

In the Summary above and in the Detailed Description of PreferredEmbodiments, reference is made to particular features (including methodsteps) of the invention. Where a particular feature is disclosed in thecontext of a particular aspect or embodiment of the invention, thatfeature can also be used, to the extent possible, in combination withand/or in the context of other particular aspects and embodiments of theinvention, and in the invention generally.

The term “comprises” is used herein to mean that other ingredients,features, steps, etc. are optionally present. When reference is madeherein to a process comprising two or more defined steps, the steps canbe carried in any order or simultaneously (except where the contextexcludes that possibility), and the process can include one or moresteps which are carried out before any of the defined steps, between twoof the defined steps, or after all of the defined steps (except wherethe context excludes that possibility).

In this section, the invention will be described more fully withreference to certain preferred embodiments. This invention may, however,be embodied in many different forms and should not be construed aslimited to the embodiments set forth herein. Rather, these embodimentsare provided so that this disclosure will convey preferred embodimentsof the invention to those skilled in the art.

The present invention is directed to systems and processes utilizingpyrolysis to produce useful products in a facile manner. It ispreferred, although not critical, that the systems be collocated with afacility such as a sawmill that generates biomass as a by-product, andwhere the exhaust from the pyrolysis process can be used to increaseefficiency. To achieve these and other objectives, an aspect of theinvention is a compact and portable system that employs a pyrolysis unitcapable of capturing and reusing heat that might otherwise be lost tothe outside environment. Several system embodiments of the inventionthat achieve these objectives are discussed herein.

In one embodiment, a batch pyrolysis system utilizes the pressuregenerated by the pyrolysis vapors to move the pyrolysis vapors and noncondensing gas to a separation point. The batch pyrolysis unit providesthe ability of processing bulky items without the need for sizedreduction while also accommodating biomass that is small in size such assawdust.

A continuously operable pyrolysis system embodiment also utilizes thepressure generated during pyrolysis to move the pyrolysis vapors and noncondensing gas to a separation point.

In some embodiments of the pyrolysis system, a closed loop heatexchanger includes an auger for biomass movement where a section of theauger housing is maintained at a temperature sufficient to transferthermal energy by radiation and conduction into the biomass forpyrolysis. In a first example, a pyrolysis unit embodying such featuresincludes an elongated, tubular auger pyrolysis chamber and a combustionchamber. The pyrolysis unit is configured generally concentrically sothat the combustion chamber is located substantially around the smallerdiameter pyrolysis chamber. A heat source is used to produce the heatedgas stream flowing through the combustion chamber. In some embodiments,the combustion chamber receives fuel and air that is ignited to producethe thermal energy by combustion. The hot combustion gases flow aboutthe pyrolysis auger housing conductively transferring thermal energythrough the auger housing into the biomass to effect pyrolysis of thebiomass being moved by the auger. Alternate embodiments use other heatsources, such as a gas turbine or other form of internal combustionengine in conjunction with a burn enclosure where additional fuel isadded to reach the desired temperature. Biomass is introduced into thepyrolysis unit and pyrolyzed by conductive and radiant heat transferthrough the auger housing resulting in the creation of non-condensinggases (NCG), pyrolysis vapor, along with carbon (char).

Fast pyrolysis occurs when the biomass is heated to the pyrolysistemperature in about two seconds or less. Pyrolysis of cellulosicbiomass typically produces 14% NCG (7% Carbon Dioxide & 7% CarbonMonoxide); 14.3% Carbon; and 79.8% pyrolysis vapor per unit mass of thebiomass.

When pyrolysis occurs in a fixed volume, the pyrolysis vapor increasesthe pressure inside the pyrolysis chamber. One of the advantages of theinvention is that, this pressure is utilized to facilitate the flow ofthe NCG and pyrolysis vapor from the pyrolysis chamber to an associatedliquid collection unit where the gases are cooled, the liquid pyrolysisoil is separated from the NCG, and collected as a product of thepyrolysis unit. This principle of operation is significantly differentthan conventional systems that use a mechanical means such as a pump orfan to generate a forced gas flow that moves the pyrolysis vapor fromthe pyrolysis chamber to the liquid collection unit. In contrast tothese conventional systems, in the systems and processes of theinvention, a majority of the pyrolysis vapor flow between the pyrolysischamber and liquid collection unit is achieved by the natural increasein pressure of the vapors with increase in temperature of the vapors.Preferably, the pyrolysis vapor flow to the liquid collection unit iseven achieved without mechanical means for forcing it thereto,

In some embodiments, the gases are directed to fuel usage equipment suchas a burner for generation of thermal energy or an internal combustionengine (ICE) for generation of mechanical and/or electrical power. Suchinternal combustion engine can be a spark ignition, compressionignition, or turbine engine.

The thermal energy source is typically a fuel air combustion burner, butin some embodiments, an electric induction or resistive thermal sourceis used to supply the thermal energy.

In some embodiments a biomass feed bin is used for introduction ofbiomass into the pyrolysis unit. In some embodiments, NCG separated fromthe pyrolysis vapor and char is passed through the biomass feed binwhereupon the biomass acts as a filter, cleaning entrained matter fromthe exhaust.

In some embodiments char produced by the pyrolysis process is collectedas a product of the process.

In yet another embodiment, the exhaust from an ICE is used as a heatsource to promote efficient pyrolysis while also producing mechanicaland/or electrical power.

In some embodiments a hot gas filter (HGF) system and method isincorporated for removing entrained char from the pyrolysis vapors andNCG prior to cooling and condensing of the pyrolysis vapors intopyrolysis oil. The HGF may include an apparatus and method for cleaningthe HGF elements in place during operation of the pyrolysis system. TheHGF system addresses a problem of char entraining with the NCG andpyrolysis vapors that flow from the pyrolysis auger housing. It is knownthat oil produced via pyrolysis that contains char is not desired, asthe char continues to react with the pyrolysis oil forming longer chainmolecules and a general increase in the viscosity of the pyrolysis oil.Removing the char particles above 2 to 3 microns reduces these degradingeffects and provides oil with an extended shelf life. Removal of thechar is accomplished prior to condensing of the pyrolysis vapors intopyrolysis oil. Specifically, the char is preferably filtered using a hotgas filter. A unique hot gas filter has been developed and is integratedwith a cyclone separator as an exit filter that is economical tofabricate and operate. It is also noted that integration of the cycloneand the HGF system reduces the number of and space required for thosemachine centers. Ensuring that the char is filtered at the requiredtemperature the outer walls of the cyclone are insulated. Hot gasfilters experience build up of the filtered material on the surface ofthe filter elements referred to as a cake. This build up of material hasthe positive effect of decreasing the size of the particle that isallowed to pass thru the filter element but the negative result ofincreasing the pressure required for the gas to flow. This increase inpressure is reflected throughout the pyrolysis unit increasing the powerto operate the unit and the pressure capabilities of the unit. As thepressure increases a point is reached where the filter elements must becleaned or replaced. The filter industry relies on a procedure of backflow of a compatible gas through the filter elements to crack orfracture the cake causing it to fall from the filter element. Thisprocedure is incompatible with the pyrolysis system potentiallyintroducing pressure and thermal shock waves; furthermore the back flowtechnique does completely clean the filter elements of the cake. Thepartial cleaning results in a shorter run time between the back flowcleaning cycles reducing the production rate of the pyrolysis system. Asthe run time becomes too short the filter elements must be removed forcleaning or replacement. A significant aspect of this invention isapparatus and methods for cleaning the filter elements while installedto provide complete removal of the char, returning the elements to aclean condition. Upon reaching a certain pressure drop across the filterelements, the biomass feed to the pyrolysis unit is stopped. Oxygen issupplied to the entrance of the cyclone HGF system. This oxygen rich gasstream causes the char caked on the filter elements to ignite and burn,forming carbon dioxide which flows through the filter elements and intothe exhaust system. The cleaning combustion air flow is controlled toprevent overheating of the filter elements and system. The pyrolysisunit is returned to the pyrolysis operation when the cleaning cycle iscompleted.

Pyrolysis oil forms submicron particles or mist during condensing withthe individual droplets having no coalescing affinity. The mistrepresents a loss in pyrolysis oil production and a potentialenvironmental problem for the system exhaust gas. In some embodimentsthe NCG and pyrolysis flow through a quench system where they are cooledbelow the condensation temperature of the pyrolysis forming pyrolysisoil. Following the quench system, the NCG may be drawn into thecombustion system for recovery of the carbon monoxide as fuel. Theresults of the combustion process are exhausted to the atmosphere. Inanother embodiment, the exhaust gas exiting the combustion system passesthrough a heat exchanger to recover thermal energy.

Referring now to FIG. 1, the pyrolysis system 10 includes a container20; an interconnecting system 30; a heat source 40; a vacuum system 50;and a liquid collection system 60.

Container 20 contains the biomass 15 prior to pyrolysis and theresulting char 16 following pyrolysis. Container 20 is removablyconnected to the interconnecting system 30 by flanges 23 and 33.

The interconnection system 30 is connected to the container 20 thoughflanges 23 and 33; to the liquid cooling system 60 through flanges 26and 34; and to the vacuum system 50 thought isolation valve 31. A gauge32 is optionally installed such that it is capable of displaying thepressure or vacuum in the interconnecting system 30.

Interconnecting system 30 provides a flow path through a vapor flowconduit 37, such as mechanical tubing isolation valve 31 to vacuumsystem 50 when isolation valve 31 is open.

Interconnecting system 30 provides a flow path though the vapor flowconduit 37 between the container 20 and the liquid collection system 60,when the isolation valve 31 is closed.

A heat source 40 is thermally linked to the container 20 for providingthermal energy for pyrolysis of the biomass 15. There are many differenttypes of heat sources 40 that are suitable, which include, but are notlimited to, combustion heat sources or electrical heat sources.

Vacuum system 50 includes a vacuum pump 51 and tubing 38. Vacuum pump 51is connected to isolation valve 31 via mechanical tubing 38.

The liquid collection system 60 includes a container 25 for the liquid17 following the pyrolysis batch. Container 25 is removably connected tothe interconnecting system 30 by flanges 26 and 34.

The liquid collection system 60 includes a unit housing 65 in which acoolant 66 is located. The coolant 66 is a material or system that iscapable of cooling the pyrolysis vapors as presented to the liquidcollection system 60. Examples of coolants include, but are not limitedto chilled water or other liquids.

Each pyrolysis batch begins with bio mass 15 being placed into container20 which is then connected to the pyrolysis system 10.

Isolation valve 31 is opened and vacuum pump 51 is enabled to remove airfrom the pyrolysis system 10 by pulling a vacuum as displayed by thegauge 32. Upon completion of establishing a vacuum; the Isolation valve31 is closed; the vacuum pump 51 stopped; and the thermal system 40engaged.

Thermal energy is rapidly introduced by the thermal system 40 to effectpyrolysis of the biomass 15 contained in the biomass container 20. Asthe biomass undergoes pyrolysis the system pressure 90, not shown, willincrease. The increase in pressure will be common to the vapor flowconduit 37. The liquid collection system 60 is in pressure communicationto the container 20 via the vapor flow conduit 37 but is thermallyisolated from the thermal energy system 40. The vapors produced by thepyrolysis will move into the liquid collection container 25 by a thermosiphon flow 55 (shown as an arrow) where they will be condensed intoliquid 17. Thermo siphon flow refers to a heat transport mechanism inwhich the vapor flow is not generated by an external pump, fan, blower,or suction device; instead the flow is generated by the pressuredifferences in the vapor that occur due to a temperature gradient. Thevapors in container 20 receive heat increasing in temperature andpressure while the vapors in container 25 are cooled decreasing intemperature and pressure. The thermo siphon flow is a result of thedifferential pressure between the container 20 and container 25.

After completion of the pyrolysis batch, the heat source 40 is removedand the system allowed to cool. After cooling, both containers 20 and 25are disconnected. The carbon 16 is removed from container 20. Thepyrolysis liquid 17 is removed from container 25. The emptied containers20 and 25 are cleaned in preparation of the next batch pyrolysis cycle.

Referring to FIG. 2 an example of a pyrolysis unit 100 and heat source40 suitable for use with the pyrolysis system 10 is depicted. Container20 is filled with biomass 15 and is placed into thermal housing 45 ofthe heat source 40. A removable top 33 is placed above the container 20with the sealing ring 23 sealing the container 20 to the removable top33 and the thermal housing 45 thus forming a closed heat exchanger.

Isolation valve 31 is opened and vacuum pump 51 enabled to draw a vacuumin the batch pyrolysis unit 100. Upon completion of establishing avacuum; the isolation valve 31 is closed; the vacuum pump 51 stopped;and the heat source 40 engaged.

Thermal energy is rapidly introduced by the heat source 40 to pyrolysisthe biomass 15 contained in the biomass container 20. The heat source 40includes a fuel 7 that is mixed with air 5 and ignited to producethermal energy by burner 41.

As the biomass undergoes pyrolysis the vapors produced will move intothe liquid collection container 25 by thermo siphon flow 55, where theywill be condensed into pyrolysis liquid 17.

Following completion of the batch pyrolysis the removable top 33 isremoved from the container 20 to allow removal of the carbon 16

FIG. 3 shows another example of a heat source 40 for pyrolysis unit 100.In this example an electric heating system 48 is used, in which anelectrical current is passed through conductors 47 to produce thermalenergy in the walls of container 20 through induction.

Turning to FIG. 4, a continuous operable pyrolysis system in accordancewith an embodiment of the invention is depicted as reference number 200.The pyrolysis system 200 includes a pyrolysis chamber 210, a heat source40, and a liquid collection system 60. Other optional features are alsoshown and described in detail below.

With continued reference to FIG. 4, the biomass feed bin 220 accepts rawbiomass 15. The present embodiment envisions receiving this biomass 15primarily from sawmills, particularly CNS facilities. The biomass 15will typically not need to be ground to a smaller size because it willalready be of a size suitable for use in the system 200. If the biomass15 does need to be ground, however, the biomass 15 will be ground priorto placing the biomass 15 in the biomass feed bin 220. Note that in thepresent embodiment, an optimal size for particles of biomass 15 used inthe pyrolysis system 200 are envisioned to be particles having no sidegenerally greater than one-quarter inch in length. In alternateembodiments, however, items of biomass 15 having substantially largerdimensions may be used. Note also that in the present embodiment, itemsof biomass 15 are envisioned to include wood chips, sawdust, bark, woodshavings, and the like. Note further that in alternate embodiments, theuse of biomass 15 of varying types received from numerous differentsources may be used. These can include environmentally problematicmaterials such as waste paper and ground tire rubber.

Still referring to FIG. 4, some biomass 15 fed into the system 200 mightrequire drying prior to undergoing pyrolysis. Biomass 15 with a moisturecontent of approximately fifteen percent or less by weight can typicallybe subjected to pyrolysis without prior drying. Green biomass 15,however, will generally have a moisture content of about fifty percentby weight, as opposed to dry biomass 15 that generally will have amoisture content of about ten percent. The green biomass 15 can beblended with the drier biomass 15 to achieve a combined moisture contentof fifteen percent or less. If such blending of the biomass 15 isinsufficient to achieve a fifteen percent moisture content by weight,then the biomass 15 will need to be dried prior to subjecting thebiomass 15 to pyrolysis. Optimally, the biomass 15 subjected topyrolysis will have a moisture content of no more than twelve percent byweight. In some cases the biomass 15 may be too dry, in which casemoisture can be added.

Continuing with FIG. 4, the pyrolysis system 200 includes a heat source40 that includes a burner 41, a combustion chamber 212, and insulationcover 211 surrounding the combustion chamber 212. Combustion fan 400draws air 5 delivering it to the inlet of economizer 242 as flow 405,(shown as an arrow). The air is heated as it flows through theeconomizer 242 and exits as flow 415 (shown as an arrow). The preheatedair is mixed with fuel 7 and ignited by igniter 12 within the burner 41.The combustion gas flow 425 (shown as an arrow) passes through thecombustion chamber 212 and exits as exhaust flow 241, (shown as anarrow). The exhaust flow 241 passes through the economizer 242 where itpreheats the air flow 405, and exits the economizer as flow 243 (shownas an arrow). Blower 230 draws the flow 243 from the economizer 242delivering it to entrainment gas storage tank 232 as flow 244 atpressure 93. Control valve 246 meters entrainment gas flow 245, (shownas an arrow) to rotary valve 247. Carbon 16, a product of the pyrolysisis delivered from the pyrolysis chamber 210 to the entraining gas flow245 and is blown into the heat system 40 as entrained carbon flow 248 asfuel for combustion.

Flow control valve 236, meters entraining gas flow 233, (shown as anarrow), through rotary valve 221. Biomass 15 is metered from biomass bin220 by rotary valve 221 and is entrained by flow 233 as flow 235.Cyclone 225 receives entrained biomass flow 235 and separates bycyclonic action the biomass from the entraining gas. The biomass iscollected by the cyclone for delivery to the pyrolysis chamber 210through rotary valve 222. The entraining gas exits the cyclone throughvalve 227 as flow 237. Control valve 227 controls the pressure 93 in thecyclone to enhance the flow of biomass into the pyrolysis chamber 210.

Biomass 15 is delivered from cyclone separator 225 by the rotary valve222 to the pyrolysis chamber 210 through pyrolysis chamber inlet 213 asflow 224 (shown as an arrow) at the pyrolysis chamber pressure 90, wherethe biomass 15 begins to receive thermal energy. The pyrolysis chamber210 acts as an open heat exchanger with the colder biomass 15 beingheated by the high temperature pyrolysis vapors that are exiting thepyrolysis chamber 210 as flow 255.

Pyrolysis chamber 210 flex joint 215 allows the pyrolysis chamber wallsto elongate during operation while maintaining a seal between thepyrolysis chamber 210 and the combustion chamber 212. This forms aclosed loop heat exchanger between the pyrolysis chamber 210 and thecombustion chamber 212 preventing oxygen remaining in the combustionprocess to enter the pyrolysis chamber 210

The pyrolysis vapors and non condensing gases exit the pyrolysis chamber210 as flow 255 through duct 217. The flow 255 enters the liquidcollection system 60, where the liquid 17 is collected into container 25by the liquid collection system 60.

Blower 262 draws the non condensing gas as flow 257 from the collectiontank 25, delivering the non condensing gas as flow 258 as combustionfuel 7 to the heat source 40.

FIG. 5 depicts an optional electric pre heater 270 that is installedbetween the rotary valve 222 and the pyrolysis chamber 210 of pyrolysissystem 200. The pre heater 270 has three resistive sections 272 that aremaintained in electrical isolation by insulator 275 with flange pattern271. The resistive sections 272 are heated by the flow of electricalenergy 277 (shown as an arrow) thereby generating thermal energy toassist in the pre heating of the biomass flow 224.

Turning to FIG. 6, a continuous pyrolysis system in accordance with thisinvention is depicted as system 300 with a pyrolysis unit 310, describedin detail below.

In this embodiment, a biomass feed bin 320 contains the biomass 15 to bepyrolized. The biomass 15 is delivered into the pyrolysis unit 310 fromthe feed bin 320 through a biomass input port 313 by a variable pitchauger 321 attached to the biomass feed bin 320. The biomass feed bin 320is capable of continually feeding biomass 15 into the pyrolysis unit310.

The pyrolysis unit 310 includes a variable pitch auger 321, an augerhousing 324, an auger drive 325, a pyrolysis gas exit pipe 327, acombustion chamber 311, and a rotary valve 328.

The variable pitch auger 321 has a first coarse pitch section 322A thatis proximate to the biomass input port 313, a second coarse pitchsection 322B that is proximate to the pyrolysis zone 326 and a finepitch section 323 that is between the coarse pitch sections 222A and222B.

Biomass 15 is fed from the biomass bin 320 by the variable pitch auger321 through the auger housing 324. The biomass 15 fills the first coursesection 322A of the variable pitch auger 321 and is increased in densityas it moves by the auger motion through the fine section 323 of thevariable pitch auger 321. The biomass 15 density increase provides aseal between the pyrolysis zone 326 and the biomass bin 320 preventingflow of the pyrolysis vapors and non condensing gas from the pyrolysiszone 326 through the auger housing 324 and the biomass bin 320. Thevariable pitch auger 321 increases to a second course pitch 322Ballowing the biomass 15 density to decrease prior to entering thepyrolysis zone 326. The biomass 15 passes through the pyrolysis zone 326where thermal energy from the combustion chamber 311, passes through theauger housing 324 causing the biomass 15 to undergo pyrolysis. Thecarbon 16 produced by the pyrolysis of the biomass 15 moves by theaction of the variable pitch auger 321 to the rotary valve 328. Thepyrolysis vapors and non condensing gases flow through the pyrolysis gasexit pipe 327 as flow 355 (shown as an arrow) to the condensing system360.

The flow 355 bubbles through a quench fluid 357 where the pyrolysisvapors are condensed and collected as pyrolysis oil 17. The noncondensing gas exits the quench chamber 361 as a draft flow 301combining with combustion air flow 305 forming combustion air and noncondensing gas flow 307. The combustion air 5 passes though a filter andis metered by a flow control valve 343 that controls the draft pressure95 of the quench container 361.

Continuing with FIG. 6, the burner 340 receives combustion air and noncondensing gas flow 307, and fuel 7 that are mixed and ignited byigniter 12. The combustion gas flow 348 passes through the combustionchamber 311 that surrounds the pyrolysis zone 326. The combustion gasflow 348 and cooling air flow 347 are drafted by induced draft blower345 and exit the system as exhaust flow 308.

The quench fluid 357 level is maintained by selecting flow 371 or 372and supply pump 375. A cooling system 377 provides closed loop coolingof the quench liquid. Pyrolysis oil 17 is removed from container 361through valve 26.

FIG. 7 is another embodiment of the system and method of a continuouspyrolysis system in accordance with this invention as pyrolysis system400 with a pyrolysis unit 380, described in detail below.

The cyclone 320 receives biomass 15 as entrained flow 315; the biomass15 is separated from the entraining gas by cyclonic action with theentraining gas exiting the cyclone 320 as flow 317. The biomass 15 isdelivered into the pyrolysis unit 380 from the cyclone 320 by a rotaryvalve 325 that is coupled to the inertia conveyor 382 though flexiblebiomass input port 381. In this way, the cyclone 320 is able tocontinually feed biomass 15 into the pyrolysis unit 380.

The pyrolysis unit 380 includes an enclosed inclined inertia conveyor382, an insulated combustion chamber 383, a foundation system 389, aninertia conveyor drive 385, a pyrolysis gas exit pipe 327, and a rotaryvalve 345.

Biomass 15 is fed from the cyclone 320 by the rotary valve 345 throughthe flexible biomass input port 381. The biomass 15 is moved through theinertia conveyor 382 by the oscillatory motion 390 induced by the actionof the dirve 385 and the parallel links 387 and 388 as constrained byfoundation 389.

The inertia conveyor 382 is substantiality surrounded by the insulatedcombustion chamber 383. The inertia conveyor 382 is heated by the flowof combustion gas 346 received from the heat source 40. The biomass 15passing through the inclined inertia conveyor 382 receives thermalenergy from the inertia conveyor 382 and undergoes pyrolysis. The carbon16 produced by the pyrolysis continues to move by the motion 390 of theinertia conveyor 382 to the rotary valve 345. The pyrolysis vapors andnon condensing gas products of the pyrolysis of the biomass 15 exit theinertia conveyor 382 through the pyrolysis gas exit pipe 327 as flow 355to the liquid collection system 60.

Heat source 40 includes a burner 41. Burner 41 receives combustion air 5and fuel 7 which are ignited by igniter 12. Rotary valve 345 deliverscarbon 16 from the inertia conveyor 382 to the burner 41 as a fuel forcombustion. The combustion gas flows into the insulated combustionchamber 383 as flow 346 and exits as flow 348. Induction fan 347 drawsthe combustion gas flow 348 and cooling air flow 349 to form exhaustflow 308.

The invention has been described above with reference to preferredembodiments. Unless otherwise defined, all technical and scientificterms used herein are intended to have the same meaning as commonlyunderstood in the art to which this invention pertains and at the timeof its filing. Although various methods and materials similar orequivalent to those described herein can be used in the practice ortesting of the present invention, suitable methods and materials aredescribed. However, the skilled should understand that the methods andmaterials used and described are examples and may not be the only onessuitable for use in the invention.

The invention has been described in some detail, but it will be apparentthat various modifications and changes can be made within the spirit andscope of the invention as described in the foregoing specification andthe appended claims.

That which is claimed is:
 1. A pyrolysis process comprising the stepsof: providing a vertically oriented pyrolysis unit having a pyrolysischamber elongated along a vertical axis thereof and a combustion chamberarranged generally concentrically and sharing a common heat-conductingwall with the pyrolysis chamber; disposing a combustion source inthermal communication with a lower end of the combustion chamber forheating the pyrolysis chamber; positioning a biomass input portproximate an upper end of the pyrolysis chamber for allowing biomassintroduced therein to fall towards a lower end of the pyrolysis chamber;providing a pyrolysis liquid collection unit in vapor communication withthe pyrolysis chamber for condensing the pyrolysis vapor to liquid;positioning the biomass input port about a proximal end of an inertiaconveyor housing for feeding biomass into an inertia conveyor housingchamber; coupling an inclined inertia conveyor to the biomass input portand extending within the inertia conveyor housing for moving the biomassalong a length of the inclined inertia conveyor to a pyrolysis zonepositioned between the proximal end and a distal end of the inertiaconveyor housing; coupling a heat source to the inertia conveyor housingpositioned proximate the pyrolysis zone for providing sufficient heat topyrolyze biomass in the pyrolysis zone; positioning a char output portproximate the distal end for removing char produced during pyrolysisfrom the inertia conveyor; and fitting a pyrolysis liquid collectionunit in vapor communication with the inertia conveyor for condensing thepyrolysis vapor to liquid.
 2. The process of claim 1, wherein thebiomass input port is positioned below a cyclonic separator thatseparates biomass from entraining gas by cyclonic action.
 3. The processof claim 1, wherein the biomass input port bisects the vertical axis ofthe pyrolysis chamber.
 4. The system of claim 1, further comprising thestep of positioning an electric heater about the biomass input port forpre-heating biomass as it flows therethrough while falling.
 5. Theprocess of claim 1, further comprising the steps of concentricallysurrounding the inertia conveyor with a combustion chamber.
 6. Theprocess of claim 1, further comprising the step of inclining the inertiaconveyor so that the proximal end is lower than the distal end.